Display apparatus

ABSTRACT

A display apparatus includes a substrate, an insulating layer, an alignment film, and a sealant. The insulating layer is disposed on the substrate and with a plurality of grooves. The alignment film is disposed on the insulating layer. The sealant is disposed on the alignment film. Wherein, the sealant overlaps at least a portion of the plurality of grooves. In a predetermined unit region, the side length of the predetermined unit region is a maximum width X of the sealant, and a total side length of the portions of the plurality of grooves located in the predetermined unit region is greater than 8 times of the maximum width X.

This is a Continuation of U.S. application Ser. No. 17/153,948, filedJan. 21, 2021, which is a Continuation application of U.S. applicationSer. No. 16/683,319, filed on Nov. 14, 2019 (now patented as U.S. Pat.No. 10,928,680, issued Feb. 23, 2021), which claims the benefit ofPeople's Republic of China application Serial No. 201811509647.1, filedon Dec. 11, 2018, the subject matters of which are incorporated hereinby reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates in general to a display apparatus, andmore particularly to a display apparatus having a liquid crystal panel.

Description of the Related Art

A panel of a typical liquid crystal display apparatus includes twosubstrates and a liquid crystal layer disposed between these twosubstrates, and an alignment film in contact with the liquid crystallayer is further provided between the substrates and the liquid crystallayer. The substrates may have a display region and a frame regionsurrounding the display region, wherein a sealant is disposed in theframe region to adhere with these two substrates.

As the development of the modern display technology, the frame region ofdisplay apparatuses is continually narrowed, the sealant originallydisposed on the frame region may contact with the alignment films, dueto lacking of space. However, the adhesion between the sealant and thealignment film may be so poor that may cause the sealant peeling fromthe substrate, and affect the quality of the liquid crystal displayapparatus.

Therefore, there is a need of providing an improved display apparatus toimprove the adhesion of the sealant.

SUMMARY OF THE INVENTION

One aspect of the present disclosure is related to a display apparatus,wherein the display apparatus includes a substrate, an insulating layer,an alignment film, and a sealant. The insulating layer is disposed onthe substrate and with a plurality of grooves. The alignment film isdisposed on the insulating layer. The sealant is disposed on thealignment film. The sealant overlaps at least a part of the plurality ofgrooves. In a predetermined unit region, the side length of thepredetermined unit region is a maximum width X of the sealant, and atotal groove side length of the plurality of grooves located in thepredetermined unit region is greater than 8 times of the maximum widthX.

According to above embodiments of the present disclosure, a displayapparatus is provided, wherein at least one insulating layer is providedon the substrate for forming a thin film transistor; and a plurality ofgrooves are formed in a portion of the insulating layer disposed in aframe region of the display apparatus. A sealant is then formed on theportion of the insulating layer disposed in the frame region to make thesealant at least overlapping a portion of the plurality of grooves.Thereby, the adhesion between the sealant and the substrates can beimproved by the increasing the surface contacts between the sealant andinsulating layer to prevent the sealant peeling from the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects of the present disclosure will become betterunderstood with regard to the following detailed description of thepreferred but non-limiting embodiment(s). The following description ismade with reference to the accompanying drawings.

FIG. 1A is a top view illustrating the structure of a display apparatusin accordance with one embodiment of the present disclosure.

FIG. 1B is a cross-sectional view illustrating a partial structural ofthe display apparatus taken along a cutting line G in FIG. 1A.

FIG. 2 is a top view illustrating the structure of an insulating layerin accordance with one embodiment of the present disclosure.

FIG. 3 is a top view illustrating a partial structure of the displayapparatus as depicted in FIG. 1A.

FIG. 4 is a top enlarged view illustrating a partial structure of adisplay apparatus in accordance with another embodiment of the presentdisclosure.

FIG. 5 is diagram illustrating the relationship between the width of asealant and its peel strength.

FIGS. 6A-6B are cross-sectional views illustrating partial fabricatingstructures of an alignment film according to one embodiment of thepresent disclosure.

FIG. 7A is a cross-sectional view illustrating a partial structure of adisplay apparatus in accordance with yet another embodiment of thepresent disclosure.

FIG. 7B are top views illustrating the partial structures of aninsulating layer and another insulating layer (as depicted in FIG. 7A)and the assembly structure thereof in accordance with one embodiment ofthe present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Present disclosure provides a display apparatus to solve the problemsthat a sealant is easily peeled off from the transparent substrate of aliquid crystal panel. In order to make the objects, features andadvantages of the present invention more apparent, several preferredembodiments are described below in detail with reference to theaccompanying drawings.

It is to be noted that the following descriptions of preferredembodiments of this disclosure are presented herein for purpose ofillustration and description only not for limiting the scope of theinvention. It is not intended to be exhaustive or to be limited to theprecise form disclosed. Also, it is also important to point out thatthere may be other features, elements, steps and parameters forimplementing the embodiments of the present disclosure which are notspecifically illustrated.

Furthermore, the use of ordinal numbers such as “first”, “second”, andthe like, as used in the specification and the claims are just used tomodify the elements in the claims. It neither mean that it has anyprevious ordinal number on behalf of the requested element, nor does itrepresent the sequence order of one request element and another requestelement. These ordinal numbers are only used for enabling a requestedelement with a certain name for distinguishing another requested elementhaving the same name. In addition, the positions mentioned in thespecification and claims, such as “above”, “upper”, “on”, “below”,“lower” or “under”, may either mean that the two elements are in directcontact, or may refer to that the two components are not in directcontact.

Those skilled in the art will be able to make equal modifications andvariations without departing from the spirit and scope of thedisclosure. In the different embodiments and the drawings, the sameelements will be denoted by the same reference numbers.

FIG. 1A is a top view illustrating the structure of a display apparatus100 in accordance with one embodiment of the present disclosure. FIG. 1Bis a cross-sectional view illustrating a partial structural of thedisplay apparatus 100 taken along a cutting line G in FIG. 1A. As shownin FIG. 1A, the display apparatus 100 has a display region 101, a frameregion 102 and a bonding region 103. The display region 101 includes aplurality of pixels 101 a for displaying an image. The frame region 102is disposed at the periphery of the display region 101 and is adjacentto the display region 101. The bonding region 103 is disposed out of oneside or more than one sides of the frame region 102. In the presentembodiment, the bonding region 103 can be disposed out of one singleside of the frame region 102, and is not limited thereto. The bondingregion 103 can be used to provide pins and pads (not shown) to be bondedto an external connection line (not shown).

In some embodiments of the present disclosure, the display apparatus 100can be a liquid crystal panel. The display apparatus 100 may include asubstrate 104, a substrate 105, a plurality of thin film transistors106, an alignment film 107, a liquid crystal layer 108, a sealant 109,an insulating layer 116, and an insulating layer 110. The substrate 105is disposed on the substrate 104, and the liquid crystal layer 108 isdisposed between the substrate 104 and the substrate 105. In order toguide the liquid crystal molecules in the liquid crystal layer 108aligning in the same direction, the alignment film 107 can be disposedon the substrate 104 and adjacent to the liquid crystal layer 108 tomake the liquid crystal molecules having a predetermined pretilt angle.The insulating layer 116 can be disposed between the alignment film 107and the thin film transistors 106, and the insulating layer 116 may be aplanarization layer. The display apparatus 100 may further include alight shielding layer 120 disposed between the substrate 105 and theliquid crystal layer 108 covering the frame region 102; and a portion ofthe light shielding layer 120 is disposed in the display region 101.Wherein a pixel light-emitting region 101 a may be a light-transmittingregion defined by the portion of the light shielding layer 120 disposedin the display region 101 (for example, the light shielding layer 120may be a black matrix, a metal layer or a filter layer overlap).Alternatively, the pixel light-emitting region 101 a may be alight-emitting region of an organic light-emitting layer in an organiclight-emitting diode. The pixel light-emitting region 101 a may also bea light emitting region in an inorganic light-emitting diode. In thepixel light-emitting region 101 a, the plural thin film transistors 106can be electrically connected to the pixel electrodes (not shown) forcontrolling the on/off state of each pixel.

The substrate 104 and the substrate 105 may be a rigid substrate or aflexible substrate. The materials of the substrate 104 and the substrate105 may include glass, polyimide (PI), polyethylene terephthalate (PET)or any other light-transmitting plate or film material suitable forforming a substrate, but it is not limited thereto. In addition,although the display apparatus 100 illustrated in the embodiment isrectangular, the shape thereof is not limited thereto. The shape of thedisplay apparatus 100 may be triangular, prismatic, trapezoidal,wedge-shaped, other polygonal or irregular with arc edges. The shapes ofthe substrate 104 and the substrate 105 may also be different, and thedimensions of these two substrates may not be strictly limited. Thedimensions of the substrate 104 and the substrate 105 can besubstantially the same or different.

Referring to FIG. 1A, in the top view, the alignment film 107 may coverthe display region 101, the frame region 102, or the bonding region 103,either partially or a whole region thereof, which is not limitedthereto. In the present embodiment, the alignment film 107 covers theentire display region 101 and the entire frame region 102. In some otherembodiments of the present disclosure, the alignment film 107 covers theentire display region 101 and a portion of the frame region 102. Thealignment film 107 may be a PI alignment film or a polymer-stabilizedalignment (PSA) film, but the material thereof is not limited thereto.

Referring to FIG. 1A and FIG. 1B, a plurality of thin film transistors106 (only one of which is shown as a representative) are formed on thesubstrate 104, wherein the thin film transistors 106 can be selectivelydisposed in the display region 101 or the frame region 102 of thedisplay apparatus 100. The thin film transistor 106 further includes adrain 106 a, a source 106 b, a gate 106 c, and an active layer 106 d.The gate electrode 106 c is disposed on the substrate 104; the activelayer 106 d is disposed over the gate 106 c, and the drain 106 a and thesource 106 b are disposed adjacent to the active layer 106 d, partiallycovering the two sides of the active layer 106 d, and separated fromeach other respectively. The drain 106 a, the source 106 b, the gate 106c, and the active layer 106 d may be formed by deposition includingchemical vapor deposition (CVD) or physical vapor deposition (PVD),evaporation, sputtering or other suitable methods, but not limitedthereto. The thin film transistor 106 is not limited to be a bottom gate(BG) thin film transistor, a top gate (TG) thin film transistor, or acombination of these two.

There may be at least one or more insulating layers disposed between thealignment film 107 and the substrate 104, and the insulating layers areformed on the substrate 104 by CVD or PVD technology for isolatingdifferent electrodes. These insulating layers may be formed of amaterial which can be either an inorganic material or an organicmaterial, and the material may be, for example, silicon nitride (SiNx),silicon oxide (SiOx) or polyfluoroalkoxy (PPA), but is not limitedthereto. In the present embodiment (in the cross-sectional view of FIG.1B), one of the insulating layers, such as the insulating layer 110, isdisposed between the source 106 b and the gate 106 c and may serve asthe gate dielectric layer of the thin film transistor 106, but notlimited thereto. In some other embodiments, the insulating layer 110 maybe disposed on the drain 106 a and the source 106 b serving as aprotective layer thereof, serving as one of organic insulating layers(PFA), or serving as one of the insulating layers disposed between thesemiconductor active layer 106 d and the substrate 104. In the top view,the insulating layer 110 may cover the display region 101, the frameregion 102, or the bonding region 103, either partially or a wholeregion thereof, which is not limited thereto. In the present embodiment,the insulating layer 110 covers the entire display region 101 and theentire frame region 102.

The portion of the insulating layer 110 disposed in the frame region 102can be formed by a semiconductor process including steps of transferringthe pattern of a reticle onto the substrate 104 by photolithography, andthen removing the portion of the insulating layer 110 that is notprotected by the photoresist, whereby the portion of the insulatinglayer 110 disposed in the frame region 102 has a plurality of grooves111 and a plurality of protrusions 110 a. The protrusions 110 a aredefined by the sidewalls 111S and 111S′ of two adjacent grooves 111 andthe top portion 110 b of the protrusions 110 a. In the presentembodiment, one of the protrusions 110 a may be a hill-like protrusion(such as a trapezoid protrusion) having the sidewall 111S or 111S′extending outward. In some other embodiments, the shape of the topportion 110 b of the protrusions 110 a and the sidewall 111S or 111S′may be at least partially curved, but is not limited thereto, whereinthe material of the protrusions 110 a is the same as that of theinsulating layer 110. In some embodiments of the present disclosure, theplurality of grooves 111 may be a plurality of continuous ordiscontinuous grooves, which may be, for example, elongated grooves.

Because the plurality of grooves 111 and the plurality of protrusions110 a may cause the topography of the insulating layer 110 uneven, thematerial for forming the alignment film 107, prior to curing, may flowalong the uneven topography and partially accommodated in the grooves111, whereby a portions of the alignment film 107 may be formed in thegrooves 111, and the top surface 107 a of the portion of the alignmentfilm 107 accommodated in the grooves 111 may not extend beyond the topportion 110 b of the protrusions 110 a. Such that a partial of thesidewalls of the protrusions 110 a (i.e. the sidewalls 111S and 111S′ ofthe grooves 111) and the top portion 110 b of the protrusions 110 a maybe (not limited to) contact with the alignment film 107, but it is notlimited thereto. In the present embodiment, the top portion 110 b of theprotrusions 110 a does not be contact with the alignment film 107, thesidewalls 111S and 111S′ of the grooves 111 can be at least partiallycontact with the alignment film 107.

As shown in FIG. 1A, the sealant 109 is disposed in the frame region 102and along the periphery of the display region 101. The shape or positionof the sealant 109 formed in the frame region 102 may not be limited andcan be varied according to the design requirements of the displayapparatus 100. In the present embodiment, the sealant 109 can be arectangular line in the top view, and the edge 109 a of the sealant 109can align the outer edge 102 a of the frame region 102. In some otherembodiments, in top view, the sealant 109 may be an irregular curve, andthe edge 109 a of the sealant 109 does not align the outer edge 102 a ofthe frame region 102. It should be noted that the sealant 109 is not anabsolutely equal width line in top view, and may have a maximum width Xwithin a sampling region. In the present embodiment, the sealant 109 hasa width ranging from 400 μm to 1500 μm and a maximum width X about 15000μm within the sampling region. In some other embodiments, the sealant109 has a width ranging from 450 μm to 850 μm. As shown in FIG. 1B, theportion of the sealant 109 disposed in the frame region 102 can beattached to the substrate 104 by selectively contacting the top surface107 a of the alignment film 107, the sidewalls 111S and 111S′ of thegroove 111 and the top portion 110 b of the protrusions 110 a. Becausethe poor adhesion between the sealant 109 and the alignment film 107,therefore, increasing, the total area of the contact surface formedbetween the sealant 109 and the top surface 110 a of the protrusion 110a by the design of the groove 111. The adhesion between the sealant 109and the substrate 104 can be improved.

Referring to FIG. 2 , the insulating layer 110 has a plurality ofgrooves 111, and each of the grooves 111 may optionally further includea sub-groove 111A, a sub-groove 111B, a sub-groove 111C, and asub-groove 111D. The long axis of the sub-groove 111A extends in thedirection L1 (for example, the Y direction); the long axis of thesub-groove 111B extends in the direction L2 (for example, the Ydirection); the long axis of the sub-groove 111C extends in thedirection L3 (for example: The X direction); the long axis of thesub-groove 111D extends in the direction L4 (for example, the Xdirection); and the sub-groove 111C or the sub-groove 111D may connectthe sub-groove 111A and the sub-groove 111B. In other words, thesub-groove 111C and the sub-groove 111D are two lateral trenches otherthan the portions overlapping with the sub-groove 111A and thesub-groove 111B. The direction L3 (X) and the direction L4 (X) aredifferent from the direction L1 (Y), and the direction L3 and thedirection L4 are different from the direction L2 (Y). The direction L1and the direction L2 may be parallel or non-parallel with each other,and may form an angle φ between each other, wherein the angle φ is lessthan 180°. In the present specification, the grooves 111 may be formedat the outer edge 102 a of the frame region 102, and the grooves 111 maybe parallel or non-parallel to each other, and are not limited thereto.The distance between the sidewalls 111S and 111S′ of two adjacentgrooves 111 may be represented as P (FIG. 2 ) that is the width of thetop portion 110 b of the protrusion 110 a. The distance P between twoadjacent grooves 111 may be equal or non-equal in width, and is notlimited thereto. In another embodiment, the sidewall 111S of the grooves111 may have some micro-roughness which can prevent the material forforming the alignment film 107 reflowing, after it flows into thegrooves 111, so that less material of the alignment film 107 may beremained on the top portion 110 b of the protrusion 110 a. This canincrease the contact area between the sealant 109 and the insulatinglayer 110 to improve the adhesion between the sealant 109 and theinsulating layer 110. When the sealant 109 is in contact with thesidewall of the insulating layer 110 having the micro-roughness (thesidewall 111S of the grooves 111), the adhesion between the sealant 109and the insulating layer 110 can also be improved. In anotherembodiment, the sidewall 111S of the grooves 111 may have a slight waveshape or a curved edge when viewed from a top view. When the substrate109 and the aligned substrates 104 and 105 are squeezed to apply stressto the sealant 109, the wave or curved shaped sidewall 111S of thegrooves 111 can contribute the support force in different directions toreduce the risk that the sealant 109 may be peeled off from thesubstrate 104.

FIG. 2 is a top view illustrating the structure of an insulating layer110 disposed in the frame region 102. In one embodiment of the presentdisclosure, the direction L1 may be parallel to the direction L2; thedirection L3 may be perpendicular to the direction L1 or the directionL4 may be perpendicular to the direction L1. In another embodiment, thedirection L1 and the direction L2 are not parallel with each other,instead forming an angle φ less than 180°. More notably, the grooves 111formed in the insulating layer 110 may selectively further include agroove 111E between two adjacent sub-grooves (such as the sub-grooves111A and 111B), but not connected with the sub-groove s 111A and 111B.In the present embodiment, the sub-grooves 111E not only is disposedbetween the two adjacent sub-grooves 111A and 111B, but also disposedbetween the two adjacent sub-grooves 111C and 111D. The sub-groove 111E,in top view, may be shaped as a rectangular, a circular, an ellipticalor other irregular shape, and is not limited thereto. The sub-groove111A, the sub-groove 111B, the sub-groove 111C, the sub-groove 111D, andthe sub-groove 111E may form a plurality of patterns having the samesize. For example, the area of each pattern may be the same, but each ofwhich may have different total side length; or the area of thesepatterns may be different, but each of which may have the same totalside length. These patterns may be selectively arranged in a regularmanner, and is not limited thereto. In some other embodiments, thesub-groove 111A, the sub-groove 111B, the sub-groove 111C, thesub-groove 111D and the sub-groove 111E may have different sizesaccording to the design requirements; the shape thereof may be notlimited to a rectangle; at least one of these patterns may have acircular or arc edge. In yet another embodiment, not every groove 111includes one sub-groove 111A, one sub-groove 111B, one sub-groove 111C,one sub-groove 111D and one sub-groove 111E. The sub-grooves 111C, thesub-grooves 111D and the sub-grooves 111E may have differentdistribution conditions and sizes according to the design requirements,and are not limited thereto.

FIG. 3 is a top view illustrating a partial structure (within a samplingregion defined by the dotted line AA) of the display apparatus 100 asdepicted in FIG. 1A. Within the sampling region (also referred to as aunit region U), the projection pattern 109 c formed by projecting theprofile of the sealant 109 onto the substrate 104 has a maximum width Xfrom the edge 109 a staying away from the display region 101 to anotheredge 109 b getting close to the display area 101, wherein theses edges109 a and 109 b serve as two opposite sides of the square unit region Uwith a side length of maximum width X. The square unit region U overlapsat least part of the grooves 111 and a portion of the sealant projectionpattern 109 c, and the area of the grooves 111 overlapping with thesealant 109 within the square unit region U is greater than or equal to50% the area of the square unit region U. The total side length of theportions of the grooves 111 that are located in the unit region U can bereferred to as the total groove side length, and the total groove sidelength is greater than 8 times the maximum width X (>8X). In the presentembodiment, since the sealant 109 has less width variation, thus anyportion of the sealant 109 disposed in the frame region 102 can besampled to serve as the square unit region U. For example, one side ofthe sealant 109 aligning the outer edge 102 a of the frame region 102can be referred to a reference side of the square unit region U; and adistance counted from the reference side and getting close to thedisplay region 101 about 1 cm or 2 cm can be referred to as the maximumwidth X; thereby the square unit region U can be figured out by usingthe reference side and the maximum width X.

Referring to FIGS. 3 and 4 , the method for calculating the total grooveside length in the unit region U is provided as follows: FIG. 4 is a topenlarged view illustrating a partial structure of the display apparatus100 in accordance with another embodiment of the present disclosure. Inthe present embodiment, as shown in FIG. 4 , the portion of the grooves111 that are located in the unit region U overlaps with the sealantprojection pattern 109 c, and the sides of the grooves 111 overlappingwith the sealant projection pattern 109 c forms six square patterns ofside length k (the total side length of each square pattern is 4 k) andsix incomplete squares (the total side length of each incomplete squarepattern is k/2+k+k/2=2 k). The total groove side length is 6×4 k+6×2k=36 k that is greater than 8 times the maximum width X of the sealant109, wherein the units of k and X are the same. The total groove sidelength in the unit region U can be expressed by the formula (1): 36 k>8X. . . (1). The aforementioned “incomplete (square)” means the (square)pattern that formed by the sides of the grooves 111 is not completelyoverlapping with the sealant projection pattern 109 c, when calculatingthe total groove length in the unit region U.

Referring to FIG. 3 again, the frame region 102 is disposed adjacent tothe display region 101; the plurality of grooves 111 are formed in theportion of the insulating layer 110 that is disposed in the frame region102; the sealant 109 has a maximum width X between the two edges 109 aand 109 b thereof; and the sealant 109 covers portions of the grooves111.

The display apparatus 100 further may optionally include at least onegate on panel (GOP) 115 disposed in the frame region 102 between theedge 109 b of the sealant 109 and the display region 101. GOP 115includes at least one thin film transistor (not shown). It is noted thatat least one of the thin film transistors in the GOP 115 may have a sizegreater than that at least one of the thin film transistor 106 disposedin the display region 101. In the present embodiment, the GOP 115 has awidth ranging from 400 μm to 800 μm.

The grooves 111 are typically disposed adjacent the outer edge 102 a ofthe frame region 102. Since the cutting line 114 is aligned with theouter edge 102 a of the frame region 102, thus the portion of the frameregion 102 out of the outer edge 102 a of the frame region 102 could becut off and does not appear in the final state of the display apparatus100 after the cutting process. However, portions of the grooves 111close to the cutting line 114 may likely be cut off by the cuttingprocess, due to the process tolerance in the cutting process. In orderto ensure that there are grooves 111 still remained in the frame region102 after the cutting process, it is necessary to form at least threegrooves 111 in the insulating layer 110 to avoid the problem ofinsufficient number of the grooves 111 in the final product, due toprocess tolerances, which may adversely affecting the adhesion ofsealant.

In the present embodiment, the edge 109 a of the sealant 109 is alignedwith the outer edge 102 a of the frame region 102, and is not limitedthereto. In some other embodiments, the edges 109 a of the sealant 109may not be alignment with the outer edge 102 a of the frame region 102.In the present embodiment, the distance from the cutting line 114 to theinner edge 102 b of the frame area 102 may range from 800 to 1000 μm(micrometers), For example, the distance may be about 900 μm.

FIG. 5 is diagram illustrating the relationship between the width of asealant 109 and the peel strength measured by an adhesion test conductedon the substrate 104 including the grooves 111 as depicted in FIG. 2 andthe sealant 109. According to FIG. 5 , it can be determined that whenthe width of the sealant 109 is small (for example, less than 500 μm),there is no difference in the adhesion strength between the sealant 109and the substrate 104 having the different number (3, 4 or 5) of thegrooves 111. However, as the width of the sealant 109 is graduallyincreased (for example, 600 μm), the adhesive strength between thesealant 109 and the substrate 104 having more than three grooves 111 isstronger than that adhesive strength between the sealant 109 and thesubstrate 104 merely having three grooves 111. Therefore, the presentdisclosure selects the substrate 104 having more than three grooves 111as the design trend of the display device 100.

FIGS. 6A-6B are cross-sectional views illustrating partial fabricatingstructures of the alignment film 107 according to one embodiment of thepresent disclosure. Referring to FIG. 6A, in the cross-sectional view,each one of the grooves 111 disposed in the frame region 102 has anopening width S which is the distance between the top portions 110 b ofthe two adjacent protrusions 110 a. If the opening width S is too large,on one hand, the total number of the grooves 111 may be sacrificed, andsufficient contact area may not be provided between the insulating layer110 and the sealant 109. On the other hand, if the opening width S istoo small, the space of the grooves 111 may be insufficient toaccommodate the alignment film 107. Such that, the opening width S needsto be limited, for the purpose of not affecting the quality of thedisplay apparatus 100.

FIG. 6A schematically shows the initial state when the alignment film107 is formed over the substrate 104, wherein a portion of the alignmentfilm 107 is formed on the top portions 110 b of the protrusions 110 a.Since the material for forming the alignment film 107 has fluidity, thusthe material for forming the alignment film 107 may flow along thetopography of the frame region 102 and reflow into the groove 111, priorto curing. As shown in FIG. 6B, the top portions 110 b of theprotrusions 110 a has no or less residual material of the alignment film107; and the top surface 107 a of the alignment film 107 in the grooves111 approach the top portions 110 b of the protrusions 110 a. However,the top surface 107 a does not exceed the top portions 110 b. In orderto preventing the top surface 107 a of the portion of the alignment film107 accommodated in the grooves 111 to exceed beyond the top portions110 b of the protrusions 110 a, the area of the grooves 111 needs to begreater than or equal to the area of the material of the alignment film107 originally accommodated in the grooves 111 plus the area of thematerial subsequent reflowing into the grooves 111. This conforms to thefollowing formula (2):

$\begin{matrix}{{\left( {S + \left( {S - {2d \times {Cot}\mspace{11mu}\theta}} \right)} \right) \times {d/2}} \geqq {{P \times t} + {S \times t}}} & (2)\end{matrix}$

Wherein, S represents the opening width of the grooves 111; P representsthe width of the top portions 110 b of the protrusions 110 a, trepresents the height of the portion of the alignment film 107 disposedon the display region 101. In the present embodiment, t may representthe thickness of the portion of the alignment film 107 disposed in thedisplay region 101 corresponding to the pixel light-emitting region 101a. The thickness of the portion of the alignment film 107 may range from0.05 μm (ie, 500 Å) to 0.15 μm or from 0.06 μm to 0.11 μm, which is notlimited thereto. Since the thickness of the alignment film 107 variesdepending on the position of measurement, thus, in one embodiment of thepresent disclosure, an average value of a three-point measurementperformed on three locations in the display region 101 can be taken toestimate the thickness of the alignment film 107 corresponding to thepixel light-emitting region 101 a, wherein d represents the height ofthe groove 111, and the units of S, P, t and d are the same. In thepresent embodiment, d may range from 0.3 μm to 1 μm, which is notlimited thereto. θ represents the angle formed by the sidewall 111S ofthe groove 111 and the bottom 110Q of the protrusion 110 a, wherein θmay range from 15° to 75°. In some embodiments of the presentdisclosure, θ ranges from 20° to 70°, which is not limited thereto.Formula (3) can be obtained by converting the formula as follows:

$\begin{matrix}{S \geqq {\left( {{P \times t} + {d^{2} \times 2\;{Cot}\;\theta}} \right)/\left( {d - t} \right)}} & (3)\end{matrix}$

In the present embodiment, the width P is about 20 μm; the height t isabout 0.1 μm; the height d is about 0.5 μm; the angle θ is about 45°;and the opening width S≥5.625 μm.

In addition, when the unit region U defined by the maximum width X ofthe sealant 109 includes only three grooves 111, the total width 3S ofthe openings (each of a widths S) of these three grooves 111 must besmaller than the maximum width X of the sealant 109, this can berepresented by the formula (4):

$\begin{matrix}{{3S} < X} & (4)\end{matrix}$

Therefore, combining the formula (3) with the formula (4) yields theformula (5), and the opening width S of the groove 111 needs to satisfythe formula (5):

$\begin{matrix}{{{1/3}X} > S \geqq {\left( {{P \times t} + {d^{2} \times 2\;{Cot}\mspace{11mu}\theta}} \right)/\left( {d - t} \right)}} & (5)\end{matrix}$

It should be noted that when the width P of the top portions 110 b ofthe protrusions 110 a is too large, the material for forming thealignment film 107 cannot reflow easily into the grooves 111, so that alarge amount of residual material of the alignment film 107 may remainon the top portion 110 b, and this may adversely affect the adhesionbetween the sealant 109 and the substrate 104. On the other hand, whenthe width P of the top portions 110 b of the protrusions 110 a is toosmall, the contact area formed between the top portions 110 b of theprotrusions 110 a and the sealant 109 may be insufficient, that alsocannot increase the adhesion between the sealant 109 and the substrate104. Therefore, those skilled in the art can obtain the formula (6)according to formula (2):

$\begin{matrix}{P \leqq {\left\lbrack {{S\left( {d - t} \right)} - {d^{2}{Cot}\mspace{11mu}\theta}} \right\rbrack/t}} & (6)\end{matrix}$

The range of the width P of the top portions 110 b of the protrusions110 a can be obtained from this formula (6). In the present embodiment,the opening width S is about 3.5 μm; the height t is about 0.1 μm; theheight d is about 0.5 μm; the angle θ is about 45°; and the width P≤11.5μm.

Referring to FIGS. 7A and 7B, FIG. 7A is a cross-sectional viewillustrating a partial structure of a display apparatus 100 inaccordance with yet another embodiment of the present disclosure; andFIG. 7B are top views illustrating the partial structures of theassembly structure of the insulating layer 110 and another insulatinglayer 112 (as depicted in FIG. 7A) in accordance with one embodiment ofthe present disclosure. In the present embodiment, the structure of thedisplay apparatus 100 as depicted in FIG. 7A is substantially similar tothat of FIG. 1B except that the display apparatus 100 depicted in FIG.7A further includes an insulating layer 112 formed on the insulatinglayer 110 by CVD or PVD technology. The portion of the insulating layer112 disposed in the display region 101 may cover at least a portion ofthe drain 106 a, the active layer 106 d, the source 106 b, and theinsulating layer 110. The insulating layer 112 may serve as apassivation layer of the thin film transistor 106, which is not limitedthereto. In some other embodiments of the present disclosure, theinsulating layer 112 can serve as a planarization layer or the like. Thematerial of the insulating layer 112 may include, for example, siliconnitride (SiNx), silicon oxide (SiOx), or an organic material.

Referring to FIG. 7A and FIG. 1A simultaneously, the insulating layer112 (at a top view angle) may cover the display region 101, the frameregion 102, or the bonding region 103, either partially or a wholeregion thereof, which is not limited thereto. In the present embodiment,the insulating layer 112 and the insulating layer 110 may cover at leasta portion of the display region 101 and at least a portion of the frameregion 102. Referring to FIG. 7A, the portion of the insulating layer112 disposed in the frame region 102 may have a plurality of grooves 113and a plurality of protrusions 113 a that are formed in the same manneras the aforementioned grooves 111, thus the materials and the method formanufacturing the same will not be redundantly described here. Theprotrusions 113 a are defined by the sidewalls 113S and 113S′ and thetop portions 113 b of two adjacent grooves 113. In the presentembodiment, one of the protrusions 113 a may be a hill-like protrusion(such as a trapezoid protrusion) having the sidewall 113S or 113S′extending outward. In some other embodiments of the present disclosure,the portion of the trapezoid protrusion disposed between the top portion113 b of the protrusions 113 a and the sidewalls 113S or 113S′ may be atleast partially curved, and is not limited thereto. The material of theprotrusions 113 a is the same as that of the insulating layer 112. Inaddition, each of the grooves 113 corresponds to one of the grooves 111and has an opening width S22. The opening width S22 is a distancebetween the top portions 113 b of the two adjacent protrusions 113 a,the opening width S22 may be the same as or different from the width Sof the groove 111, and is not limited thereto.

It should be noted that, in the top view, at least one portion of thegrooves 113 do not overlap with the corresponding grooves 111, and atleast one portion of the grooves 111 do not overlap with thecorresponding grooves 113. As shown in FIG. 7B, in the same region, theprojection pattern B that formed by projecting the profiles of theplurality of grooves 113 onto the substrate 104 overlaps with theprojection pattern A formed by projecting the profiles of the pluralityof grooves 111 onto the substrate 104. In the projection pattern C(obtained by the overlapping of the projection pattern A and theprojection B), the sidewalls 111S′ of the grooves 111 is not alignedwith and not parallel to the sidewalls 113S of the grooves 113. Forexample, in the present embodiment, the plurality of grooves 111 formedin the insulating layer 110 may include a plurality of strip-shaped(e.g. rectangular) elongated grooves; and the plurality of grooves 113formed in the insulating layer 112 may include multiple elongatedgrooves having irregular shapes, such as (but not limited to) S-shaped,zigzag, twist-shaped or other irregular patterned grooves; but which isnot limited thereto.

Moreover, the shape, size, and stacking order of the aforementionedgrooves 111 and grooves 113 are not limited thereto. For example, inanother embodiment of the present disclosure, the plurality of grooves113 formed in the insulating layer 112 may include a plurality ofstrip-shaped elongated rectangular grooves; and the plurality of grooves111 formed in the insulating layer 110 may include a plurality ofirregular shaped elongated grooves.

As shown in FIG. 7A, since the sealant 109 may extend into the grooves111 and the grooves 113, thus the contact area formed between thesealant 109 and the insulating layers 110 and 112 can be increased, soas to improve the adhesion between the sealant 109 and the substrate104. In addition, referring to FIG. 7B, in the range of sampling, thetotal groove side length in the unit region U is calculated by thefollowing manners: the total side length of the portion of the grooves111 disposed in the unit region U plus the total side length of theportion of the groove 113 disposed in the unit region U; and any side oredge of the grooves 111 and 113 (disposed in the unit region U) that cancontribute the adhesion of the sealant 109 should be included in thecalculation of the total groove side length.

In detail, as shown in FIG. 7B, for example, there are three grooves 111partially located in the unit region U that is defined/sampled in theprojection pattern C. Each of the grooves 111 has two sides extendingfor a length r in the unit region U along the long axis L71. The totalside length of the portions of the side of the three grooves 111 locatedin the unit region U is 3×2r. There are three grooves 113 located in theunit area U. Each of the grooves 113 has two sides extending for alength w in the unit region U along the long axis L72. The total sidelength of the portions of the side of the three grooves 113 located inthe unit area U is 3×2w. The total groove length of the portions ofgrooves 111 and the grooves 113 located in the unit area U is 3×(2r+2w),wherein the unit of r and w is the same.

It should be noted that although FIG. 7A and FIG. 7B only show twolayers of partially overlapping insulating layer 110 and insulatinglayer 112, in other embodiments of the present disclosure, the displayapparatus 100 may include more similar structures of insulating layers.The pattern and stacking manner of the grooves are not limited. Thoseskilled in the art can vary the number of insulating layers and thepattern and stacking manner of the grooves according to the designrequirements of the display apparatus 100 to improve the adhesionbetween the sealant 109 and the substrate 104.

According to above embodiments of the present disclosure, a displayapparatus is provided, wherein at least one insulating layer is providedon the substrate for forming a thin film transistor, and a plurality ofgrooves are formed in a portion of the insulating layer disposed in aframe region of the display apparatus. An alignment film and a sealantare then formed on the portion of the insulating layer disposed in theframe region to make the projection of sealant onto the substrate atleast overlapping with a portion of the plurality of grooves. Thereby,the surface contacts between the sealant and the insulating layer can beincreased, and the adhesion between the sealant and the substrate can beimproved by the aid of the surface contacts to prevent the sealant frombeing peeled off from the substrate.

While the invention has been described by way of example and in terms ofthe preferred embodiment (s), it is to be understood that the inventionis not limited thereto. On the contrary, it is intended to cover variousmodifications and similar arrangements and procedures, and the scope ofthe appended claims therefore should be accorded the broadestinterpretation so as to encompass all such modifications and similararrangements and procedures.

What is claimed is:
 1. A substrate assembly, comprising: a substrate; aninsulating layer, disposed on the substrate and having a plurality ofgrooves; a polyimide film, disposed on the insulating layer; and asealant, overlapped with at least a portion of the plurality of grooves;wherein in a top view and in a sampling region U, a width X of thesealant is a distance between an edge and another edge of the sealant;wherein the insulating layer comprises a top portion of a protrusionwith a width P disposed between two adjacent grooves of the plurality ofthe grooves; one of the two adjacent grooves has an opening with anopening width S and a sidewall; wherein the sidewall and a bottom of theprotrusion form an angle θ, and the opening width S satisfies a formulaas follows: 1/3X > S ≧ (P × t + d² × 2 Cot  θ)/(d − t); wherein t is aheight of the polyimide film, d is a height of one of the plurality ofgrooves, and X, S, P, t and d have the same unit.
 2. The substrateassembly according to claim 1, wherein the plurality of grooves arestrip-shaped elongated grooves.
 3. The substrate assembly according toclaim 1, wherein the edge of the sealant has a curved shape.
 4. Thesubstrate assembly according to claim 1, further comprising a displayregion and a frame region adjacent to the display region, wherein thesealant is disposed in the frame region.
 5. The substrate assemblyaccording to claim 4, wherein the edge is away from the display region,and the another edge is close to the display region.
 6. The substrateassembly according to claim 1, further comprising a display region and aframe region adjacent to the display region, wherein the plurality ofgrooves are disposed in the frame region.
 7. The substrate assemblyaccording to claim 6, wherein the polyimide film is disposed in thedisplay region.
 8. The substrate assembly according to claim 6, furthercomprising a thin film transistor disposed in the frame region.
 9. Thesubstrate assembly according to claim 1, wherein the insulating layer isformed of an organic material.
 10. The substrate assembly according toclaim 1, wherein the insulating layer has more than three grooves. 11.The substrate assembly according to claim 1, wherein in a top view, atleast a part of the protrusion has a curved shape.
 12. A substrateassembly, comprising: a substrate; an insulating layer, disposed on thesubstrate and having a plurality of grooves; an alignment film, disposedon the insulating layer; and a sealant, overlapped with at least aportion of the plurality of grooves; wherein in a top view and in asampling region U, a width X of the sealant is a distance between anedge and another edge of the sealant; wherein the insulating layercomprises a top portion of a protrusion with a width P disposed betweentwo adjacent grooves of the plurality of the grooves; one of the twoadjacent grooves has an opening with an opening width S and a sidewall;wherein the sidewall and a bottom of the protrusion form an angle θ andthe opening width S satisfies a formula as follows:⅓X>S≥(P×t+d ²×2 Cot θ)/(d−t); wherein t is a height of the alignmentfilm, d is a height of one of the plurality of grooves, and X, S, P, tand d have the same unit.
 13. The substrate assembly according to claim12, wherein in a top view, at least a part of the protrusion has acurved shape.